The session language can be used to set how the following elements are displayed on the server, based on language and cultural preference:
The language that will be used for error and other system messages. SQL Server supports having multiple copies of all system error strings and messages in all the languages in which SQL Server is available. These messages can be viewed in the sys.messages catalog view. When you install a localized version of SQL Server, these system messages are translated for the language version that you install. By default, you also obtain the U.S. English set of these messages. Additionally, you can add user-defined messages in a specific language by using sp_addmessage.
The format of date and time data.
The names of days and months, including abbreviations.
The first day of the week.
There are 33 languages available for use as session settings. For a list of languages, see sys.syslanguages.
To set the session language from the server side, use SET LANGUAGE.
The session language can be set on the client side by using OLE DB, ODBC or ADO.NET. For OLE DB, use the SSPROP_INIT_CURRENTLANGUAGE property. For more information, see Initialization and Authorization Properties.
For ODBC, use the Language keyword. For more information, see SQLConfigDataSource.
For ADO.NET, use the Current Language parameter of the ConnectionString object. For more information, see the Microsoft Data Access Components (MDAC) software development kit (SDK) documentation.